The sudden popularity of assisted living facilities in the U.S. left a gap in the regulation of the industry. According to the Department of Health and Human Services, there are more than 31,000 assisted living homes in the country that house nearly 750,000 people.

The federal government regulates nursing homes, but not these assisted living facilities. That’s the job of the states that often aren’t prepared to regulate such rapidly expanding industries. With more and more people choosing to live in these facilities, in “Life and Death in Assisted Living,” FRONTLINE and ProPublica looked into how much regulation there is and whether or not these homes are actually safe.